Israel is building a massive barrier in the West Bank. It is mostly a fence, but some of it is a concrete wall.
The Israeli government says the barrier helps prevent Palestinian suicide bombers travelling to Israeli cities to kill Israelis. It says it is only temporary and can be removed once a peace agreement is reached.
Palestinians say it is creating a new border and cutting into land they hope will form a future state of Palestine. They also say the barrier cuts through Palestinian villages and land, stopping farmers from getting to their land.
The United Nations and countries including America and the UK have said they don't think the barrier is a good idea.